Madrid wasted little time asserting their dominance over the Asian champions and duly took advantage through Vinicius just 13 minutes into the contest.
Federico Valverde added a second five minutes later, but that seemed to spark Al Hilal back to life as Moussa Marega halved the deficit following a clinical counter-attack.
Any hopes of a comeback, however, were quickly dashed after the restart as both Karim Benzema and Valverde found the back of the net to delight the 44,439 in attendance.
Vinicius would later add his second of the game – bookended by goals from Luciano Vietto – to cap off an impressive tournament for the Brazilian, one that earned him Golden Ball honours.
Los Blancos’ fifth Club World Cup title now takes their overall global tally to eight, and manager Carlo Ancelotti was delighted to add another piece of silverware to their decorated cabinet.
“We are very happy,” Ancelotti said after the match. “For the eighth time, Real Madrid is world champion.
“We made a good game, with a lot of quality up front. Vinicius, Benzema, Valverde… they have done very well.
“They showed skills and quality. It was great.”
With Ancelotti’s European champions top of the podium ahead of Al Hilal, it was Flamengo who earned third place after defeating Al Ahly 4-2 earlier on Sunday (AEDT).